• Journal of The Korean Society of Integrative Medicine
• /
• v.8 no.3
• /
• pp.53-62
• /
• 2020

Purpose :Periodontal ligament stem cells maintain tissue homeostasis in periodontal ligament. The purpose of this study was to determine the characteristics of periodontal ligament stem cells isolated from premolar teeth and observe protective effects against oxidative damage caused by Triethylene glycol dimethacrylate (TEGDMA) following treatment with N-acetylsysteine amide (NACA) drug known as enzymatic antioxidants. Methods : Primary periodontal ligament stem cell (PDSC) culture was performed from simply extracted human premolar of orthodontic patients. The characteristics of the primary cultured PDSCs was analyzed using the FACS system. PDSCs was incubated with TEGDMA and NACA. The cell proliferation and survival was determined using WST-1 assay. Collected data were analyzed using SPSS Window 20. Results : Primary cultured PDSCs grow on the floor and develop rapidly in a cluster form from up to 14 days. The morphology of PDSCs showed the spindle-shaped cells and grew directionally. FACS analysis, In addition, positive expression of visible cells were observed in mesenchymal stem cell biomarkers. PDLSCs cell viability was significantly decreased at high concentration in both 3 and 6 hours after TEGDMA treatment. We observed a decrease in the number of cells as well as a morphological change of PDLSCs. Antioxidative effect was notable since the death of PDLSC death was significantly inhibited compared to the control group at 24 and 48 hours after NACA treatment. Conclusion : Therefore, based on the results of this study, further research should be encouraged considering the development of clinical treatment methods using various antioxidants as well as regenerative engineering techniques utilizing periodontal ligament stem cells.

• Animal Bioscience
• /
• v.34 no.4
• /
• pp.533-538
• /
• 2021

Objective: Pluripotent stem cell-derived lymphatic endothelial cells (LECs) show great promise in their therapeutic application in the field of regenerative medicine related to lymphatic vessels. We tested the approach of forced differentiation of mouse embryonal stem cells into LECs using biodegradable poly lactic-co-glycolic acid (PLGA) nanospheres in conjugation with growth factors (vascular endothelial growth factors [VEGF-A and VEGF-C]). Methods: We evaluated the practical use of heparin-conjugated PLGA nanoparticles (molecular weight ~15,000) in conjugation with VEGF-A/C, embryoid body (EB) formation, and LEC differentiation using immunofluorescence staining followed by quantification and quantitative real-time polymerase chain reaction analysis. Results: We showed that formation and differentiation of EB with VEGF-A/C-conjugated PLGA nanospheres, compared to direct supplementation of VEGF-A/C to the EB differentiation media, greatly improved yield of LYVE1(+) LECs. Our analyses revealed that the enhanced potential of LEC differentiation using VEGF-A/C-conjugated PLGA nanospheres was mediated by elevation of expression of the genes that are important for lymphatic vessel formation. Conclusion: Together, we not only established an improved protocol for LEC differentiation using PLGA nanospheres but also provided a platform technology for the mechanistic study of LEC development in mammals.

• Journal of Korean Neurosurgical Society
• /
• v.53 no.4
• /
• pp.207-212
• /
• 2013

Objective : Recent studies have shown encouraging progress toward the use of autogenic and allogenic mesenchymal stem cells (MSCs) to arrest, or even lead to partial regeneration in, intervertebral disc (IVD) degeneration. However, this technology is still in its infancy, and further development is required. The aim of this study was to analyze whether rat adipose-derived mesenchymal stem cells (ADMSC) can differentiate towards IVD-like cells after treatment with transforming growth factor ${\beta}3$ (TGF-${\beta}3$) in vitro. We also performed quantitative analysis of gene expression for ADMSC only, ADMSCs treated with TGF-${\beta}3$, and co-cultured ADMSCs treated with TGF-${\beta}3$. Methods : ADMSCs were sub-cultured to homogeneity and used in fluorocytometry assays for CD11, CD45, and CD90/Thy1. ADMSCs were differentiated in spheroid culture towards the chondrogenic lineage by the presence of TGF-${\beta}3$, dexamethasone, and ascorbate. We also co-cultured pure ADMSCs and nucleus pulposus cells in 24-well plates, and performed immunohistochemical staining, western blotting, and RT-PCR for quantitative analysis of gene expression. Results : Results of fluorocytometry were positive for CD90/Thy1 and negative for CD11 and CD45. TGF-${\beta}3$-mediated induction of ADMSCs led to the expression of the differentiation markers of intervertebral disc-like cells, such as aggrecan, collagen II, and sox-9. Co-cultured ADMSCs treated with TGF-${\beta}3$ showed higher expression of differentiation markers and greater extracellular matrix production compared with ADMSCs treated with TGF-${\beta}3$ alone. Conclusion : ADMSC treated with TGF-${\beta}3$ may be an attractive source for regeneration therapy in degenerative IVD. These findings may also help elucidate the pathologic mechanism of MSC therapy in the degeneration of IVD in vivo.

• Journal of the Korean Society of Tobacco Science
• /
• v.27 no.1 s.53
• /
• pp.94-99
• /
• 2005

To correct the difference of filling volumn for various cut tobacco and puffed stem according to moisture contents, correction equation was estamated by a simple regression analysis. The $R^2$(coefficient of determination) of correction equation was above 0.95. To verify the precision of correction equation, we predicted correction equation of other samples. The filling volumns by the difference of $1\%$ moisture content were $0.018\;~\;0.022cc/g$ (cut tobacco) and 0.060cc/g (puffed stem). The precision of correction equation for various cut tobacco was very high, but that of puffed stem was low due to quality deviation of row stem according to a season.

• Proceedings of the KSPS conference
• /
• 2004.05a
• /
• pp.143-146
• /
• 2004

The aim of this paper is to investigate how the stem-final consonant clusters beginning with the liquid /ㄹ/ in Korean are realized in speech. Most scholars claim that the Korean stem-final consonant clusters are simplified and reduced to a stop consonant when pronounced. An attempt is made in this paper to verify the claim by conducting a series of listening tests and an acoustic analysis. The listening tests show that, contrary to the previous claims, some Koreans actually pronounce the stem-final consonant clusters as a whole. The result of the spectrographical study confirms our auditory observation. It has been found that the duration time taken by the stem-final consonant clusters is clearly longer when both consonants are pronounced than when only a liquid is pronounced. Similarly the vowel length of the previous syllable in the former is found to be longer in scale than the latter.

• The Korean Journal of Mycology
• /
• v.51 no.2
• /
• pp.141-146
• /
• 2023

Stem rot symptoms were observed in Gondre (Cirsium setidens) plants growing in a vinyl greenhouse in Taebaek, Korea during a disease survey in June 2022. The plants presented with dark brown to black rot on the stems at or above the soil line. Severely diseased plants displayed wilt and blight. Disease incidence among these plants ranged from 1 to 5%. Three isolates of Rhizoctonia sp. were obtained from the stem lesions of diseased plants. All isolates were identified as Rhizoctonia solani AG-2-2(IV) based on the morphological and cultural characteristics, results of the anastomosis test, and phylogenetic analysis. The pathogenicity of the isolates to Gondre plants was confirmed using an artificial inoculation test. The lesions induced by the inoculation test were similar to those observed in the investigated vinyl greenhouse. Here, we report a case of R. solani AG-2-2(IV) causing stem rot in Gondre.

• Journal of Korean Society of Forest Science
• /
• v.108 no.4
• /
• pp.592-599
• /
• 2019

This study aimed to develop an equation for estimating stem volume for Larix kaempferiin South Korea using independent variables, diameter at breast height (DBH), and height as being closely associated with stem volume. Analysis was conducted on the growth performance of 2,840 Larix kaempferi samples across South Korea after felling them and gleaning diameter data according to both stem height and stem analyses. In order to test the fitness of six different stem taper equations, empirical assessment was conducted for fitness index (FI), bias, mean, and absolute deviation (MAD), and coefficient variation (%CV). The two selectedmodels found to be optimal were the following: model one (V=a+bDBH²), established by employing DBH only; and model four (V=a+bDBH²H), established by utilizing DBH and height, respectively. The findings of non-linear regression indicated statistical significance (p < 0.05) in a and b, which were the coefficients for the intercepts and slopes of the models. The FI of the models ranged between 94% and 99%, and the bias was close to zero, while MAD ranged from 0.01 to 0.05, and %CV from 5.97 to 14.43, indicating a high level of fitness. Thus, using the suggested models, the basic information necessary for forest management was obtained, and an estimation of the stem volume was effected without delay soon after effecting DBH and height measurements.

• Animal Bioscience
• /
• v.37 no.6
• /
• pp.1021-1030
• /
• 2024

Objective: R-loops are DNA:RNA triplex hybrids, and their metabolism is tightly regulated by transcriptional regulation, DNA damage response, and chromatin structure dynamics. R-loop homeostasis is dynamically regulated and closely associated with gene transcription in mouse zygotes. However, the factors responsible for regulating these dynamic changes in the R-loops of fertilized mouse eggs have not yet been investigated. This study examined the functions of candidate factors that interact with R-loops during zygotic gene activation. Methods: In this study, we used publicly available next-generation sequencing datasets, including low-input ribosome profiling analysis and polymerase II chromatin immunoprecipitation-sequencing (ChIP-seq), to identify potential regulators of R-loop dynamics in zygotes. These datasets were downloaded, reanalyzed, and compared with mass spectrometry data to identify candidate factors involved in regulating R-loop dynamics. To validate the functions of these candidate factors, we treated mouse zygotes with chemical inhibitors using in vitro fertilization. Immunofluorescence with an anti-R-loop antibody was then performed to quantify changes in R-loop metabolism. Results: We identified DEAD-box-5 (DDX5) and histone deacetylase-2 (HDAC2) as candidates that potentially regulate R-loop metabolism in oocytes, zygotes and two-cell embryos based on change of their gene translation. Our analysis revealed that the DDX5 inhibition of activity led to decreased R-loop accumulation in pronuclei, indicating its involvement in regulating R-loop dynamics. However, the inhibition of histone deacetylase-2 activity did not significantly affect R-loop levels in pronuclei. Conclusion: These findings suggest that dynamic changes in R-loops during mouse zygote development are likely regulated by RNA helicases, particularly DDX5, in conjunction with transcriptional processes. Our study provides compelling evidence for the involvement of these factors in regulating R-loop dynamics during early embryonic development.

• Journal of Life Science
• /
• v.14 no.2
• /
• pp.339-344
• /
• 2004

Identification of individual quantitative trait loci (QTL) is a prerequisite to application of marker-assisted selection for stern length. Two simple sequence repeat (SSR)-based linkage maps were constructed from recombination inbred line populations between cross of Keunolkong and Shinpaldalkong. Two parents used differed greatly in stem length, which were 30.57 cm and 49.75 cm in Keunolkong and Shinpaldalkong, respectively. Using the constructed maps, regression analysis and interval mapping were performed to identify QTLs conferring stem length. Four QTLs for stem length on linkage groups (LG) F, J, N and O were identified in the Keunolkong ${\times}$ Shinpaldalkong population and they totally explained 37.83% of variation for stem length. In the population, two major QTLs on LG J and O conditioning 14.25% and 10.68% of the phenotypic variation in stem length were determined and two QTLs with minor effect were detected on LG F and N. Identification of QTLs for stem length and mapping individual locus should facilitate to describe genetic mechanisms for stem length in different population. SSR markers tightly linked to QTLs for stem length allow to accelerate the elimination of deleterious genes and selection for desirable recombinants at early stage in crop breeding programs.

• Journal of Genetic Medicine
• /
• v.12 no.1
• /
• pp.31-37
• /
• 2015

Purpose: We investigated the neurogenic potentials of amniotic fluid-derived stem cells (AFSCs) according to the expression levels of stem cell markers and ingredients in the neural induction media. Materials and Methods: Four samples of AFSCs with different levels of Oct-4 and c-kit expression were differentiated neurally, using three kinds of induction media containing retinoic acid (RA) and/or a mixture of 3-isobutyl-1-methylxanthine/indomethacin/insulin (neuromix), and examined by immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR) for their expression of neurospecific markers. Results: The cells in neuromix-containing media displayed small nuclei and long processes that were characteristic of neural cells. RT-PCR analysis revealed that the number of neural markers showing upregulation was greater in cells cultured in the neuromix-containing media than in those cultured in RA-only medium. Neurospecific gene expression was also higher in Oct-4 and c-kit double-positive cells than in c-kit-low or -negative cells. Conclusion: The stem cell marker c-kit (rather than Oct-4) and the ingredient neuromix (rather than RA) exert greater effects on neurogenesis of AFSCs.